Process for the fast cooking of pasta

ABSTRACT

In a process for the fast cooking of pasta and the like, a metered quantity of food is introduced from the top, into a containing chamber 8 embodied in a boiler 7, in said containing chamber 8 pasta being homogeneously distributed. Subsequently water at high pressure and temperature coming from the boiler is also introduced into the containing chamber. The expansion of water in the containing chamber takes place without forming over-heated vapor so that water can homogeneously impregnate and soften pasta within a period shorter than 40 seconds. Pasta is then conveyed into a pause chamber 9 where cooking goes on for a period shorter than 40 seconds. The last cooking operation takes place in the consuming vessel 76 where pasta is finally transferred, while the final consumer is putting dressing thereon.

This is a division, of application Ser. No. 123, 110, filed Oct. 19,1987, now U.S. Pat. No. 4,869,160.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a process for the fast cooking ofpasta and the like, in particular of dry "spaghetti" and other kinds offilamentary pasta to be consumed immediately and to the automaticapparatus to put the process into practice

2. Prior Art

In known apparatus food is usually cooked during two steps, the firstone taking place in a so-called cooking or pre-cooking chamber which ishydraulically brought into contact with a boiler to receive hot watertherefrom in order to carry out the cooking Then food is discharged intoan expansion chamber, under atmospheric pressure, in which cookingterminates during a period substantially as long as the first step. Foodready to be consumed is then unloaded into an appropriate earthenwarevessel put at the outside.

This process however is adapted to give an acceptable cooking degreeonly if it takes place within a period of 10 to 20 seconds longer thanone minute. From a commercial standpoint this time is too long and it isdifficult to reduce it owing to an improper operation during the firstcooking step. This is mainly due to the high differential values inpressure and temperature existing between boiler and cooking chamberthat give rise to the formation of dry and/or overheated vapour whilewater is introduced into said cooking chamber. The presence ofoverheated vapour alters the molecular structure of gluten present inthe pasta and it also makes the pasta surface immediately impervious topenetration by water, which remarkably hinders the absorption of waterby the latter during the different cooking steps. It is clear that inthis way the cooking operation is delayed and in many cases evenendangered.

SUMMARY OF THE INVENTION

An object of the invention is to eliminate the above drawbacks byproviding a process and an apparatus that, by suitable devices, areadapted to allow pasta to be cooked in very reduced times, shorter thanone minute.

Another object of the invention is to provide an apparatus having asimplified structure as compared to that of known apparatus.

These objects are substantially achieved, in accordance with the processin reference, by the use of an appropriate thermodynamic processinitially providing a moderate-speed expansion of the water coming fromthe boiler and flowing into a pasta-containing chamber, in order toensure a quick and homogeneous heat exchange between water-saturatedvapour and food. The true cooking of pasta takes place during acontrolled pause step which is partly carried out in a chamber underatmospheric pressure and partly in the consumer's vessel when withdrawnfrom the apparatus and while dressing is applied.

The apparatus adapted to carry out this process and to meet the proposedrequirements uses a low-evaporation-index boiler, into which is partlyplunged and penetrated a containing chamber where the heat exchangebetween water, vapours flowing thereinto and food takes place.

Advantageously the apparatus does not use any electric valve but a newtype of combined-effect valve mechanically controlling the introductionof water and vapour into a containing chamber, the discharging of thesoftened food into a pause chamber and the thermal expansion of thewater contained in the boiler by effect of heat applied in order to heatsaid water.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become moreapparent from the detailed description of a preferred embodiment of aprocess for the fast cooking of pasta and the like and of an apparatusfor putting the process into practice, according to the presentinvention, given hereinafter by way of non-limiting example withreference to the accompanying drawings in which:

FIG. 1 is a diagrammatic view of the apparatus in question sectionedalong different vertical planes;

FIG. 2 is a top view of the metering device for said apparatus;

FIG. 3 is a sectional view of the apparatus taken along line I--I ofFIG. 1;

FIG. 4 is an interrupted view on an enlarged scale of the meteringdevice seen in FIG. 2;

FIG. 5 shows the combined-effect valve fitted for the apparatus inquestion on an enlarged scale and sectioned along line II--II of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, reference numeral 1 globally denotes anapparatus for the fast cooking of pasta and the like according to thepresent invention.

Apparatus 1 is divided into two distinct bodies:

one body A including a box-shaped support 2, a base plate 3, an upperplate 4 and an openable rear cover 5; all electric components ofapparatus 1 are enclosed in body A;

second body B including a box-shaped envelope enclosing all mechanicalmembers forming the apparatus in itself, i.e.: a boiler 7; a containingchamber 8 incorporated within boiler 7; a pause chamber 9 divided by adiaphragm filter 10 defining, at the upper part thereof, an expansionportion 9a in the pause chamber 9; a combined-effect valve 11 enclosedbetween boiler 7 and pause chamber 9. The boiler 7, chamber 9 andcombined-effect valve 11 interposed therebetween are integral to oneanother, for example through screw-threaded elements, and are mounted onsupport 2 by two supporting elements 13 acting on boiler 7 and on pausechamber 9 respectively. Box-shaped envelope 6 is preferably designed tobe removable so that an easy cleaning of the members contained in body Bis possible.

A metering device 13 is disposed above the upper plate 4 and isinterlocked to a first reduction means 14 shown diagrammatically andfastened, at the upper part thereof, to the upper plate 4.

The containing chamber 8 extends vertically inside boiler 7 and has onewall portion 8a in common with the body of boiler 7 and a second wallportion 8b extending inside said boiler. The second wall portion 8badvantageously has a thinner thickness than the first wall portion 8awhich means a thinner thickness than the body of boiler 7. In this waythe different factors of liquid-to-solid and solid-to-solid thermalconductivity are harmonized.

In addition, said containing chamber 8 is intended to slightly have theform of a truncated cone the smaller base of which faces downwardly andis closed by a base wall 8c spaced apart from the boiler 7 bottom by adistance equal to one fifth of the whole height of boiler 7. By virtueof this expedient the containing chamber 8 does not suffer from thetemperature variations taking place in the lower part of boiler 7.

The inner height of the containing chamber 8 is preferably 10 to 15%greater than that of the food (spaghetti) to be contained and the innerdiameter thereof is substantially identical to the diameter of thesection occupied by spaghetti when introduced into the containingchamber 8.

Above the containing chamber 8 is located a closing ball-shaped valve 15which is normally closed and operable, through a movement-transmittingshaft 16', by control means consisting of a second reduction means 16fastened to support 2. In greater detail, the closing valve 15 iscoaxially fastened through screws 17 between a funnel-shaped flange 18and an aperture provided on the upper part of the containing chamber 8.

The containing chamber 8 communicates with boiler 7 via an outflow duct19 partly shown by a section plane offset with respect to the mainsection plane in FIG. 1. Outflow duct 19 extends from the upper end ofboiler 7 and leads off to the bottom of the containing chamber 8 acrossa diffuser 19i alocated therein.

The containing chamber 8 further communicates with a pause chamber 9through a passage port 20 extending from the chamber 8 base. Along saidoutflow duct 19 and passage port 20 a first shutoff valve 21 and asecond shutoff valve 22 are respectively interposed, both embodied inthe combined-effect valve 11. In greater detail, both shutoff valves 21and 22 are designed to have respective movable parts 21a and 22arotatably and sealingly accommodated in respective housings located inthe valve body 12 and engaged with each other by a joint 23. Shutoffvalves 21 and 22 can be simultaneously operated by a third reductionmeans 24 through a movement-transmitting shaft 24'. Valves 21 and 22 actaccording to opposite shutoff steps, that is they stop the fluidcommunication along the outflow duct 19 when passage port 20 is open andviceversa.

In an original manner the movable part 21a of the first shutoff valve 21is essentially comprised of a frusto-conical element, preferably made ofcharged PTFE rotatably accommodated in a housing 21b of truncatedconical form located in the valve body 12 across the outflow duct 19which crosses the valve body 12. The frusto-conical element 21a ispierced by a transverse through hole 78 intended to be disposed inalignment with the outflow duct 19 in order to open the fluidcommunication along the same.

Furthermore, two presser elements 79a and 79b are associated with thefrusto-conical elements 21a and they act on the bigger and smaller basethereof respectively. At least two screw threaded tie rods 80longitudinally cross the frusto-conical element 21a at diametricallyopposed positions thereof and act on presser elements 79a and 79btending to move them closer to each other. Frusto-conical element 21a isthrusted into housing 21b by a compression spring 81 between the biggerbase of the frusto-conical element 21a and a locating plate 82 fastenedto the valve element 12. In addition, a safety valve 25 (FIG. 5) ishoused in the valve body 12 and a discharge duct 26 is associatedtherewith; said discharge duct 26, starting from the outflow duct 19,makes boiler 7 communicate with pause chamber 9. Safety valve 25 issubstantially comprised of a pin obturator 27, preferably made ofcharged PTFE integral to a thin diaphragm 28 and incapsulated in a stiffpresser element 29 on which a precisely regulated spring 30 acts. Safetyvalve 25 opens when, due to thermal expansion of water or for any otherreason, pressure inside boiler 7 goes beyond a predetermined safetyvalue.

Boiler 7, closed at the bottom by a flanged cover 31 fastened thereto bymeans of bolts 32, is provided with an electrical resistor for heatingpurposes 33, the terminals 33a of which are connected to a suitableoperation switch, not shown. Said switch is interlocked to a thermostat34 and an operation circuit for a pump 35 sending water from an externalsource to boiler 7.

In greater detail, pump 35 is in communication with boiler 7 through adelivery pipe 36 along which a first pre-heating section 37 and a secondpre-heating section 38 are formed. The first pre-heating section is inthe form of a coil pipe and extends at the upper part of the pausechamber 9, that is in the expansion chamber 9a. The second pre-heatingsection 38, in the form of a coil pipe as well, is incorporated in theboiler 7 walls close to the upper part thereof. The water crossing it istherefore heated by withdrawing heat in excess from the upper part ofboiler 7 where heat tends to store. Water, after crossing the secondpre-heating section 38 is then discharged, through an outlet duct 39,into the lower part of boiler 7 in order to make temperature of watercontained in boiler 7 as much homogeneous and constant as possible.

An overpressure valve 35a and a non-return valve 35b are associated withpump 35; they ensure a constant water pressure along pipe 38 and, as aresult, in boiler 7.

Pause chamber 9 is of cylindrical form and is closed at the bottom by amovable cover 40 ensuring the tightness thereof by means of a flat seal41. Cover 40 is fastened to a cranked arm 42 fulcrumed on a pivot pin 43operated, through a movement-transmitting shaft 44, by a fourthreduction means 45, fastened to support 2 as well. Close to the base ofthe pause chamber 9 there is a plurality of drainage holes 46,hydraulically communicating with a water trap 47 along the vertical axisof which a water gauge pipe can be moved; said pipe, communicating withthe outside, is adapted to suitably adjust the excess water in the pausechamber 9 during the cooking operation.

The diaphragm filter 10 is comprised of a substantially cylindricaldiffuser 49 standing upright in front of the passage port 20. Preferablydiffuser 49 should have a diameter equal to one half the diameter of thepause chamber 9. The diffuser base is closed by one network-structuredfiltering element 10a. Around the top of diffuser 49 there is a secondfiltering element 10b the outer edge of which is linked to the innerwall of pause chamber 9 above the passage port 20. Obviously it is alsopossible to provide for a single filtering element crossing chamber 9according to a single plane disposed above the passage port 20 anddissociated from diffuser 49.

The metering device 13 is substantially comprised of a substantiallycircular rotatable base 50 rotatably engaged about a vertical axiswithin a housing 50a integral to the upper plate 4. Base 50 is also fitfor freely rotating within a ringlike element 51 secured to the upperplate 4 by spacing screws 52. The fixed ring-like element 51 is disposedso that it is coplanar with the rotatable base 50 and is provided withan unloading opening 53 located above the closing valve 15. Preferablythe unloading opening 53 is out of alignment with the projection of thevertical axis of the containing chamber 8, having a lag of about 10°(see FIG. 2). In order to emphasize the presence of the unloadingopening 53, the lefthand part of the metering device 13 in FIG. 1 hasbeen sectioned along a plane which is angularly offset with respect tothe main section plane of FIG. 1. Provision is made for a plurality ofrectangular containing compartments 54 (six in the drawing) integrallydisposed on the rotatable base 50; they are open at the top and projectbeyond the perimeter of the rotatable base 50 by a portion slightlysmaller than the width of the fixed ringlike element 51. Eachcompartment 54 has two side walls 55 connected, on the side of the fixedringlike element 51, to the opposed ends of a circumferential wall 56.

Side walls 55 and walls 56 are cut over the whole portion projectingfrom the perimeter of base 50 according to a plane parallel to the planeof the rotatable base 50, so that they give rise to open areas 54a inthe lower part of each compartment 54 and above the fixed ringlikeelement 51.

As more clearly described in the following, separation means acts on thefixed ringlike element 51; it includes a partition 57 standing uprightfrom the fixed ringlike element across the unloading opening 53 andclose to the edge of the rotatable base 50.

A curvilinear adjustment member 58 the height of which is substantiallyequal to that of partition 57 is fulcrumed on the fixed ringlike element51 through a pivot pin 59 integral and perpendicular with the latter.The adjustment direction of the rotation performed by the base 50 duringoperation of the metering device 13.

As more clearly shown in FIG. 4, adjustment means is associated with theadjustment member 58; the adjustment means includes a finger 60 engagingwith an elongated hole 61 located in the adjustment member 58. Finger 60is eccentrically engaged with a stem 61 rotating about its own verticalaxis. In this way an angular rotation of stem 61 brings about adisplacement of the adjustment member 58 about pivot 59 which results inthe free end of the adjustment member 58 moving close to or away frompartition 57. In this way it is possible to meter the amount of pastawhich is thrusted into the unloading opening 53 through a narrowpassageway 63 created between the free end of the adjustment member 58and said partition 57.

A pushing element 64 is associated with each containing compartment 54;it is slidably engaged along the side walls 55 and exactly at the baseof the same where horizontal millings are machined. Spring means acts oneach pushing element 64 in order to push the same towards the fixedringlike element 51. Said spring means consists of a rod 66 rotatablyengaged, at the opposed ends thereof, to the rotatable base 53 and to aplate 67 integral to the containing compartments 54. The rod 66 has anintermediate threaded portion 66a along which an adjustment disc 68carrying pulling springs 69 is engaged. Said springs, by their endsopposite the disc 68 act on respective cranked levers 70 each of thembeing fulcrumed on a pivot pin 71 extending between the side walls 55 ofa corresponding compartment 54.

In this way the amount of pasta loaded into each compartment 54, bypouring off the standard content of a packet for example, is submittedto a compacting pressure by the corresponding pushing element 64. On therotatable base 50 also acts operating means comprised of a lever 72which is caused to rotate by the reduction means 14 and cyclicallyengages, through a roller 73 rotatably engaged at a free end thereof,radial cavities 74 located on the lower face of the rotatable base 50.In this manner, by each travel performed by roller 73 according to thecircumference shown in dotted line at 73' in FIG. 2, the rotatable base50 undergoes an angular displacement of ##EQU1## During thisdisplacement, before the corresponding department 54 reaches theunloading opening 53, the displacement of pasta contained therein isinterferred by the presence of the adjustment member 58 causing theseparation from the peripheral wall 56 of the entire compact blockformed by pasta within the compartment 54.

In the last portion of angular displacement, partition 57 carries outthe separation of a metered amount of pasta from the above mentionedblock. The quantity intended for each dose depends upon the positioningof the adjustment member 58. In more detail said dose first undergoes aclear separation from the block of pasta along the whole height thereof,while still keeping a certain degree of verticality and compactnesscontrolled by the walls of partition 57 and adjustment member 58. Thevalue of said separation is determined by the thickness of partition 57.

When the metered amount of pasta is brought onto the unloading openings53, it loses its compactness and drops into the containing chamber 8 inan orderly way.

After the above description the operating cycle of the apparatus inquestion is as follows.

It is supposed that the containing compartments 54 have already beenfilled with pasta to be cooked and that the electrical resistor 33 hasalready carried out the heating of water in boiler 7 until a pressure of4 to 6 atm and a temperature of 130° C. to 150° C. have been reached insaid boiler 7. When an electric circuit is closed by manually orautomatically operating a switch not shown, the closing valve 15 whichis normally closed opens. As a result the first reduction means 14associated with the metering device 13 is sequentially operated. Thelatter therefore carries out the introduction of a predetermined dose ofpasta into the containing chamber 8, at the same instant in which valve15 completely opens. During this step, as clearly seen in the figures,the dose of pasta drops vertically into the containing chamber 8 and ishomogeneously distributed according to the whole section of thecontaining chamber 8.

Immediately after the dropping of said dose the closing of valve 15 isautomatically caused, preferably upon command of a microswitch operatedby lever 72. The valve closing in turn controls: opening of the firstshutoff valve 21, closing of the second shutoff valve 22, start of pump35, as well as operation of electrical resistor 33, when it is notoperating yet. Under this situation, water contained in boiler 7 ispushed into the containing chamber 8 through the outflow duct 19 anddiffuser 19b being first converted into saturated wet vapour, due to thedifference in pressure existing between boiler 7 and containing chamber8.

In an original manner, the expansion of vapour in the containing chamber8 is suitably controlled and restrained not only by diffuser 19a, butalso by pasta which is disposed adjacent the diffuser 19a in the form ofa filter bed. In this way it is advantageously possible to introducewater under a relatively high pressure into the containing chamber 8,without any risk of forming overheated vapour. In fact overheated vapourcould only be produced if fluid flowing into the containing chamber 8would have the possibility of freely expanding.

Water and vapour flowing into the containing chamber 8 rapidlyimpregnate pasta thus causing the softening of the same. Advantageously,the high pressure created inside the containing chamber 8 causes pastato be homogeneously impregnated before the occurrence of the subsequentsoftening. Should not this be the case, pasta could not be homogeneouslyimpregnated because the softening thereof would cause the closure ofpores and intermolecular spaces that have to be passed through by thefluid for impregnating purposes. The configuration of the containingchamber 8 and the disposition thereof inside boiler 7 cause thecontaining chamber 8 to be filled with water and vapour without any heatexchange with the outside taking substantially place.

The filling step of the containing chamber 8 being over, the thirdreduction means 24 is operated upon command of a timer suitablyregulated according to a time in the range of 20 to 40 seconds from thepreceding operation of the combined-effect valve 11. The third reductionmeans 24 causes the first shutoff valve 21 to be closed and,simultaneously, the second shutoff valve 22 to be opened. Under thissituation both food and water with vapour surrounding the food and beingabsorbed by it are ejected into the pause chamber 9 by effect ofpressure existing in the containing chamber 8.

While pasta and fluid are conveyed from the containing chamber 8 intothe pause chamber 9, water and vapour which during the preceding stephad impregnated the food are ejected from the food itself due to theoccurrence of changes in pressure during the specified conveyance.

When pasta comes out of the passage port 20 at high speed, it encountersdiffuser 49 which, by suitably deviating the trajectory thereof,arranges the same so that, after dropping onto the movable cover 40, itappears homogeneously distributed over the whole surface thereof.

Subsequently pasta is allowed to pause in chamber 9, where it isseparated from vapour and water in excess. In greater detail, vapour,rising along the pause chamber 9 and passing through filter 10, deliversheat to the first pre-heating section 37 so that it condenses almostcompletely and falls down onto the bottom of chamber 9 in the form ofwater. The non-condensed excess vapour is evacuated through a pipe 75leading off to the outside of the apparatus. The excess water is on thecontrary eliminated through the water gauge pipe 48 suitably disposed inthe water trap 47.

During its staying in chamber 9, pasta reabsorbs part of the cookingwater with which it is allowed to lie. While reabsorbing water, pastagoes on cooking which causes the mineral substances contained therein(that is phosphorus, potassium, magnesium, calcium, sodium, chlorine) tobe converted into mineral salts.

Before pasta has completely absorbed the cooking water, the movablecover 40 is lowered. In greater detail, the lowering of movable cover 40is carried out by a fourth reduction means 45, upon command of a furthertimer suitably regulated according to a time ranging from 20 to 40seconds from the moment in which the ejection of pasta from the pausechamber 9 took place.

The lowering of cover 40 causes the food and the cooking water not yetabsorbed to be transferred into a vessel 76 suitably disposed under thepause chamber 9, within a recess 77 provided in apparatus 1.

Afterwards vessel 76 can be withdrawn from the apparatus in order toallow dressing to be put thereon by a final consumer.

While dressing is applied, cooking of pasta is brought to an end bymeans of the total absorption of cooking water (and added dressing) towhich corresponds the organoleptic transformation of gluten present insaid pasta.

The invention attains the intended purposes.

It is to be noted in fact that, as compared to similar apparatusinvolving more complicated structures which, on the other hand, areincomplete as regards the control of thermodynamic processes duringoperation, the present invention enables a very compact and simpleconstruction, consisting of a number of component pieces as much reducedas possible and ensuring a great reliability. Furthermore, the recoveryof heat carried out by coil pipes 37 and 38, which on the other hand areindispensable to thermal stability of the machine and for eliminatingvapour from the surrounding atmosphere, allows electric energy to beremarkably saved.

In addition and above all, the apparatus in question, by virtue of thedevices adopted therein carries out the cooking of pasta within muchmore reduced times with respect to those of the known art and in abetter manner.

Modifications and variations are possible in order to conform theapparatus to the different requirements and to the type of food to becooked, without departing from the scope of the present invention, asdefined in the appended claims.

What is claimed is:
 1. A process for the fast cooking of pasta,comprising the following steps:vertically introducing a predeterminedamount of pasta into a containing chamber, said pasta being homogenouslydistributed in the whole section of the containing chamber; filling thecontaining chamber with cooking water and saturated wet vapor underpressure, said water and vapor flowing at controlled speed through thewhole section of the containing chamber and homogeneously impregnatingpasta; ejecting pasta, water and vapor from the containing chamber andconveying them into a pause chamber having a lower pressure than thatcreated in the containing chamber during the preceding step; separatingexcess vapor and cooking water from the pasta; keeping the pasta in saidpause chamber together with a predetermined amount of cooking water fora period of time sufficient for the pasta to partially reabsorb saidpredetermined amount of cooking water while simultaneously cooking saidpasta therein; and transferring pasta and residual cooking water into avessel, where cooking of pasta is brought to an end by the completeabsorption of residual water.
 2. The process as claimed in claim 1,wherein the filling step is carried out by flowing water into saidcontaining chamber, from the bottom thereof, at a temperature rangingbetween 130° C. and 150° C. and at a pressure of 5 to 8 atm.
 3. Theprocess as claimed in claim 1, wherein the filling step substantiallytakes place free of any heat exchange with the chamber walls and thesurrounding atmosphere.